Analysis Of Time Triggered Schedulers In Embedded System
73
International Journal of Computer Science & Informatics, Volume-1, Issue-1,2011
Analysis Of Time Triggered Schedulers In Embedded System
E.Anbarasi
1
N.karthik
1
1
M.E Pervasive computing Technologies, Anna University of technology, Tiruchirappalli, India.
1
Email:{ anbuek ,nkarthikapce}@gmail.com
Abstract:
In embedded software, scheduler is one of the
essential component. It is essential to schedule the task in a
suitable way to achieve the system optimization. Time
triggered scheduling approaches render a reliable
performance for real time systems. This paper sketches on
time triggered schedulers which tends to results in highly
predictable system behavior. Despite many scheduling
approaches, time triggered cooperative and time triggered
hybrid schedulers have more attention in resource
constrained embedded system which works on single
processor. Our target of this work is to analyze these time
triggered schedulers’ performances. We evaluated and
studied the performance of those time triggered schedulers
with various parameters. The results have been incurred by
implementation of schedulers in embedded c programming
language with simulation tool.
Keywords: schedulers; time triggered co-operative; time
triggered hybrid
.
I. INTRODUCTION:
Embedded system can be viewed as a
processor to perform one or more dedicated function
with computing constraints. Most of the embedded
systems are real time system for producing the output
within the predefined time limit. The embedded
system works in resource constrained environment.
So the proper scheduling mechanism helps the
system to function reasonably. Scheduler can be
specified as a set of coding that allows the process or
task directed to the CPU for execution. Scheduler can
be defined as a simple operating system that allows
tasks to be called periodically or on a one shot basis
[6]. The allocation of the task to the processor
depends on the type of scheduling methodology.
The two common approaches used in
scheduling embedded systems are event triggered and
time triggered. In event triggered, tasks are involved
as a response to events represented by the external
interrupts. On the other hand, the primary substitute
to the event triggered system is time triggered system
where the tasks are involved periodically under the
control of the timer.
Fig.1 Embedded System
Here we are considering the time triggered
cooperative (TTC) and time triggered hybrid (TTH)
scheduling coming under the time triggered
approach often applied in the low cost control system
and safety related application where the task
characteristics are known priori. The primary reason
for preferring the time triggered approach for the
application is that the results in the system are highly
predictable in nature.
In this paper we have analyzed the
performance of time triggered co-operative and time
triggered hybrid schedulers by using the following
parameters: Design of scheduler, power saving
mode, memory allocation, and response to external
events, run time overhead, choice of execution,
scalability, portability and flexibility.
Organization of the paper:
The remainder of this paper can be
organized as follows. Section II clarifies about the
various time triggered scheduling approaches and
scheduler components. The parameters and system
environment are reported in the section III. Section
IV explains about the analysis and result. Finally
Hardware
Software
Scheduler
Processor
Schedule
the task